Filtering  device

ABSTRACT

The invention relates to a filtering device comprising multiple filtering embodiments ( 3 ), the bodies of which define a longitudinal axis, said filtering elements ( 3 ) being arranged adjacently to one another in a housing such that the longitudinal axes of the filtering elements run parallel to one another. The bodies of at least some of the filtering elements ( 3 ) have a shape that deviates from a circular cylinder at least one part of the body length. The filtering device is characterized in that the filtering elements ( 3 ) with bodies that have a shape which deviates from a circular cylinder that have a cross-section the size of which at least partially changes from one end to the other end, and said filtering elements are oriented in the housing such that the regions of a larger cross-section are associated with the regions of a smaller cross-section in adjacent filtering elements.

The invention relates to a filtering device comprising a plurality offiltering elements, the bodies of which define a longitudinal axis, saidfiltering elements being arranged adjacently to one another in a housingsuch that the longitudinal axes of the filtering elements run parallelto one another, and the bodies of at least some of the filteringelements have a shape that deviates from a circular cylinder in at leastone part of the body length. The invention further relates to afiltering element that is provided for use in such a filtering device.

Filtering devices of this kind are often used in technical facilitiesfor the purpose of filtering process liquids, pressure liquids such ashydraulic oils, coolant lubricants, for treating liquid media and thelike. Facilities that use such filtering devices can often only providea limited amount of usable space for incorporating or attaching thefiltering device. However, to be able to filter correspondingly largevolume flows, the filtering surface that is provided by the filteringdevice must be sufficiently large. With regard to this requirement, aknown filtering device of the kind as specified above has beendescribed, for example, in DE 10 2004 026 862 A1; said device providesfor filtering elements having bodies that deviate from the cross-sectionof a circular cylinder form, having the form of a Reuleaux triangleinstead. In comparison to devices having circular cylindrical orblock-shaped filtering elements, the shape of the Reuleaux triangleallows for accommodating a larger filtering area inside a giveninstallation space.

On the basis of this prior art, it is the object of the presentinvention to provide a filtering device that allows for a furtherimprovement of the ratio between the installation space and theachievable filtering area.

According to the invention, this object is achieved with a filteringdevice having any and all of the characterizing features as set forth inclaim 1.

As specified in the characterizing portion of claim 1, this object⁻isachieved according to the invention in that the filtering elements withcross-sections deviating from the cross-section of the circular cylindershape have cross-sections the size of which changes, at least in part,from one end to the other end, and in that said filtering elements areoriented in such a way inside the housing that, in filtering elementsthat are adjacently disposed relative to each other, such areas withlarger cross-sections are paired with such areas having smallercross-sections. Correspondingly, in a group of filtering elementscontaining filtering elements that are disposed next to each other andpaired with each other and thereby forming a single group, more slenderareas are disposed across from the thicker areas of the adjacentlydisposed partner element, such that any free spaces or unused “deadspace” within the group can be minimized, meaning it is possible toachieve a correspondingly high packing density with an optimally largefiltering area.

Especially advantageously, filtering elements in form of tapered candlefilters are used, which are disposed adjacently in relation to eachother and with the tapering thereof oriented in opposite directions,respectively. In this case, the filtering elements that are arrangedinto a group of adjacently disposed filtering elements delimitfunnel-type fluid spaces inside the filter housing. Obvious combinationsof convex external geometries with concave structures are also possible.This way, for example, it is possible to combine layer-cake-likefiltering elements with each other by providing that one convexlayer-cake-like ring, in each case, engages in a concave recess betweentwo adjacently disposed convex layer-cake-like rings of the otherfiltering element, preferably while maintaining a radial spacing. Asidefrom such a stepwise ring arrangement, continually changing structuresare conceivable as well, which provide for a barrel-like filteringelement having a central, convexly protruding barrel part that engages,leaving a spacing, in a concave recess of an adjacent filtering elementhaving a hose-like configuration, such that a rotational hyperboloid isformed. The abovementioned spacings between individual filteringelements are necessary for any sensible routing of the fluids inside thefilter housing, and all of the filtering elements constituted in thismanner are preferably configured as rotationally symmetrical.

In especially advantageous embodiments, however, the filtering elements,which are preferably tapered candle filters, are disposed inside thefilter housing between a planar base plate and a cover plate that isdisposed in a parallel plane in relation to the former. Thecorresponding result is a pot-shaped filter housing that receives thefiltering elements by means of mounts on the base plate. Furthermore, anaxial spacing exists between the ends of the filtering elements inrelation to the top cover plate.

Especially advantageously, the base plate can be configured as aconnection plate and provided with fluid openings that can be used tobring fluid passages in fluid communication with the inner filteringcavities of the filtering elements, which are held by the ends thereofon the base plate.

With candle filters having a tube-like support structure and a filteringmedium surrounding the inside filtering cavity, especiallyadvantageously, it is possible to provide for an arrangement whereby theends of the tube-like support structure, which are allocated to the baseplate, constitute the fluid passages and engage with the fluid openingsof the base plate, when the filtering element is in the functionalposition thereof.

On a base plate that serves as a connection plate, it is possible toprovide a closure piece located at the ends of the tube-like supportstructure on the filter candles, where the inner filtering cavities areallocated to the cover plate, and said closure piece seals saidfiltering cavity in a fluid-proof manner.

Regarding the connection of the candle filters that are directed towardthe base plate by the slender ends thereof, the arrangement can beadvantageously configured such that the tube-like support structure isextended by a connection tube, which engages in the related fluidopening and that is axially secured on the base plate.

If candle filters are provided that include an external tube-likesupport structure, said support structure can form a radially protrudingannular edge on the thicker end thereof. For candle filters having thethick end thereof oriented toward the base plate, this edge can be acontact area on the base plate.

On the more slender end, the internal support structure can form acylinder part, which passes through a hollow cylindrical collar on theslender end of the external support structure, wherein the collar isaxially secured on the cylinder part. After disengaging this securitymeans, the external support structure of the candle filter can be pulledoff, for example, to replace the filter medium.

Especially advantageously, the collar can include a step constituting ashoulder, which is disposed in the radial plane, and the annular edge ofthe external support structure of the respectively adjacent candlefilter grips there-across. The annular edge of the external supportstructure thus constitutes a stop element for axially securing thecandle filters inside the group.

To support the candle filters on the cover plate, it is possible toprovide spacers, respectively, on the collar of the external supportstructure and on the closed thicker end of the internal supportstructure; preferably, they are formed thereto in one piece.

Another subject-matter of the present invention is a filtering elementthat is provided for use in the context of a filtering device accordingto any one of the claims 1 to 12 and having the characteristics of theclaim 13.

However, groups of filtering elements having varying cross-sections thatare combined with such filtering elements having identicalcross-sections inside the same filter housing, for example in thecustomary cylindrical design, also fall within the scope of the presentinvention.

The invention will be described in further detail below based on theembodiment that is represented in the drawing.

Shown are as follows:

FIG. 1 is a schematically simplified functional sketch of a perspectivetransverse view of a part of the base plate of the filter housing and apartial group of the filtering elements of an embodiment of thefiltering device according to the invention disposed thereupon;

FIG. 2 is a schematically simplified longitudinal section of a view ofonly a partial group of tapered candle filters on a partial section ofthe base plate of the embodiment;

FIG. 3 is a perspective view of only the external support structure of acandle filter for use in the embodiment of the filtering device;

FIG. 4 is a perspective transverse view, drawn as enlarged in comparisonto FIG. 3, of only the more slender end of the external supportstructure from FIG. 3;

FIG. 5 is a sectional view, drawn as enlarged in comparison to FIG. 2,of only the part from FIG. 2 that borders on the base plate;

FIG. 6 is a sectional view, drawn as correspondingly enlarged, of onlythe partial area from FIG. 2 that borders on the cover plate, which isnot shown; and

FIG. 7 is a perspective transverse view, drawn as greatly enlarged incomparison to FIG. 1, of only the partial area of the group of candlefilters from the group as shown in FIG. 1 that borders on the coverplate.

FIG. 1 only depicts a partial section of the base plate 1, which is partof the embodiment of the filtering device according to the inventionthat shall be presently described and that is part of a filter housing,which is not shown in further detail, and accommodates a plurality offiltering elements formed as tapered candle filters 3 (in FIG. 1, notall of the candle filters are identified by reference numerals). Asshown in FIG. 1, the candle filters 3 are grouped as densely packed,wherein the order thereof as provided is as follows:

in one given row, the candle filters 3 are oriented with the moreslender ends thereof towards the base plate 1 and, in the respectivelygiven adjacent row, the candle filters 3 are oriented with the thickerends thereof toward the base plate 1; moreover, the sequential rows ofcandle filters 3 are offset in relation to one another, respectivelyfollowing such an arrangement in that the candle filters 3 that arecomprised in consecutive rows are disposed inside the gaps left by therespectively previous row.

Only a partial group of the total number of candle filters 3 is depictedin FIG. 1. The side wall, constituting a hollow cylinder, and the coverplate disposed in a parallel plane opposite in relation to the baseplate 1 have also been omitted. During the filtration process, theinternal space of the filter housing that surrounds the candle filters 3constitutes the untreated side 51 (FIGS. 5 and 6), and untreated fluidthat must be cleaned can be supplied thereto via a fluid inlet. The baseplate 1 is configured as a connection plate and includes a fluid opening5 for each candle filter 3 (in FIG. 1, not all of the candle filters areidentified by reference numerals). The candle filters 3 are held orclamped between the cover plate and the base plate 1 in such a mannerthat the fluid passages 7 and 9, see FIGS. 2 and 5, which are disposedat the thicker end or the more slender end of the candle filters 3,respectively, are in fluid communication with the openings 5 of the baseplate 1. These fluid passages 7, 9 constitute the outlet from of therespective internal filter cavity 11 of the candle filters 3,constituting the clean side during the filtration process, such that thecleaned fluid flows out of the filter housing via the openings 5 of thebase plate 1.

It can be clearly discerned in FIGS. 2, 3 and 6 that the candle filters3 each feature an identical tapering. The ends of the filter cavities11, however, are configured differently, depending on whether the candlefilters 3 are disposed in fluid communication with the openings 5 by themore slender ends thereof or by the thicker ends thereof. Moreprecisely, the filter cavity 11, which is open at the bottom end due tothe passages 7 and 9, and connected by the openings 5 of the base plate1, is closed at the end that is depicted as the top end in the drawing.Regarding tapered candle filters, it is known in the art that atube-like internal support structure 13 defines the internal filtercavity 11. As most clearly visible in FIG. 6, on the candle filters 3that are closed at the more slender ends thereof, a cylinder part 15,which is formed in one piece to the end of the support structure 13,constitutes the closure of the filter cavity 11. However, on thethicker, closed end, an end part 19 of the internal support structure13, with screwed-in closure plug 17 that is configured as having aclosed wall part, constitutes the closure piece of the internal filtercavity 11.

A filter mat 21, disposed on the outside of the internal supportstructure 13 can be provided, for example, as a non-woven filtrationmaterial, such as a non-woven polyester or the like, which is placedaround the support structure 13; alternately, a fiber application can bedirectly applied to the support structure 13 by means of a melt-blownprocess. It is understood that the type and specification of therespective filter medium 21 will depend on the purpose of use and theoperating conditions of the filtering device.

At the end that is oriented toward the base plate 1, the internalsupport structure 13 forms, together with the closed end part 19, aconnection piece 23 for the engagement in the corresponding opening 5 ofthe base plate 1. The candle filters 3 that are oriented with the moreslender ends thereof toward the base plate 1 include, instead of thecylinder part 15 serving as closure piece, a connection tube 25 that isformed in one piece with the internal support structure 13 and passesthrough the related opening 5. The tube 25, and thereby the candlefilter 3, is axially secured inside the opening 5. In the presentexample, a bayonet catch 27 is provided for this purpose 27.Alternately, providing a clip for securing the screwed connection isalso possible.

In the present example, the candle filters 3 include an external,tube-like support structure 29 that surrounds the outer side of thefilter medium 21, which is shown separately in FIG. 3. The outer supportstructure 29 is a grate-like structure, like the internal supportstructure 13, preferably press-formed in one piece of a plasticmaterial, and it can accommodate a through-flow of fluid through theopenings that are provided by the grate structure. At the thicker end,the support structure 29 forms a radially protruding annular edge 31,which rests against the base plate 1 in the installed state. Formed inone piece with the opposite, closed end of the support structure 29 is aremoval part 33, showing a removal ring 35 for manually extracting thefiltering element from the filter housing. The outer support structure29 is connected to the cylinder part 15 by a bayonet attachment means37, which is hinted at only in FIG. 4. After releasing the bayonet 37,the external support structure 29 can be drawn off and removed.Corresponding to the removal part 33 of the respectively closed ends ofthe candle filters 3, the removal parts 39, which are disposed on thethicker, closed ends, are provided with the removal rings 41,corresponding to the removal rings 35 on the more slender ends.

The annular edges 31 on the external support structure 29 form a kind oftoothing with the more slender ends of the external support structure 29of adjacent candle filters to provide mutual, axial cohesion of thegroup of the candle filters 3. More precisely, as shown particularly inFIG. 6, the external support structures 29 include on the ends thereof acollar 43 that forms a type of a hollow cylinder, and the cylinder part15 of the internal support structure 13 passes there-through. Saidcollar 43 constitutes a circumferential step 45 that forms a shoulderarea 47, which is disposed in the radial plane, and that reaches overthe annular edge 31 of the thicker end of the external support structure29 of the respectively adjacent candle filter 3, as demonstratedparticularly in FIGS. 5 and 6.

With the group of candle filters 3 cohesively held together in thismanner by the base plate 1, the untreated side 51 is sealed off from theclean side, that is located inside the filter cavity 11, by means ofsealing edges 53 that are formed, as hinted at in FIG. 5, on the collar43 of the internal support structure 13. Furthermore, there exists theoption of backwashing the candle filters 3 by reversing the fluid flowfrom the clean side 11 in the direction of the untreated side 51.

In the preceding, the tapered candle filters 3 were described ascomprising multiple structural parts with support structures 13, 29 andfilter medium 21 disposed there-between; however, the candle filters canbe envisioned as tapered slotted screen tube elements that would bedisposed in corresponding groups having a reversed tapering in relationto each other.

1. A filtering device comprising multiple filtering elements (3), thebodies of which define a longitudinal axis, said filtering elements (3)being arranged adjacently to one another in a housing such that thelongitudinal axes of the filtering elements run parallel to one another,and the bodies of at least some of the filtering element (3) have ashape that deviates from a circular cylinder in at least part of thebody length, characterized in that the filtering elements (3) with ashape that deviates from a circular cylinder form have a cross-sectionthe size of which changes at least partially from one end to the otherend, and in that said filtering elements are oriented inside the housingsuch that the areas having larger cross-sections are paired with areasof smaller cross-sections in adjacent filtering elements.
 2. Thefiltering device according to claim 1, characterized in that thefiltering elements are disposed as tapered candle filters (3)withrespectively opposite tapering and as adjacent in relation to eachother.
 3. The filtering device according to claim 1, characterized inthat the filtering elements, which are preferably tapered candle filters(3), are disposed inside the filter housing between a planar base plate(1) and cover plate that is disposed in a plane parallel thereto.
 4. Thefiltering device according to claim 1, characterized in that the baseplate (1) is constituted as a connection plate and provided with fluidopenings (5) that can be brought in fluid communication with the fluidpassages (7, 9), which lead at the ends of the filtering elements (3),that are retained on the base plate (1), to the internal filter cavitythereof.
 5. The filtering device according to claim 1, characterized inthat the candle filters (3) are provided with a tube-like internalsupport structure (13) and a filter medium (21) surrounding the internalfilter cavity (11), and in that the ends of the tube-like supportstructure (13) that are allocated to the base plate (1) constitute thefluid passages (7, 9) and engage in the fluid openings (5) of the baseplate (1).
 6. The filtering device according to claim 1, characterizedin that, at the ends of the candle filters (3) allocated to the coverplate, the internal filter cavity (11) of the filtering device is closedby a closure piece (15, 17) that is disposed at the end (19) of thetube-like support structure (13).
 7. The filtering device according toclaim 1, characterized in that, on the candle filters (3) that areallocated to the base plate (1) at the slender ends thereof, thetube-like support structure (13) is extended by a connection tube (25)that engages in the corresponding fluid opening (5) and is axiallyattached to the base plate (1).
 8. The filtering device according toclaim 1, characterized in that the candle filters (3) include, on theouter side thereof, an external tube-like support structure (29) thatforms a radially protruding annular edge (31) on the thick end.
 9. Thefiltering device according to claim 1, characterized in that theinternal support structure (13) forms a cylinder part (15) on the moreslender end thereof that reaches through a hollow cylindrical collar(43) on the slender end of the external support structure (29) and isdetachably axially secured to the cylinder part (15).
 10. The filteringdevice according to claim 1, characterized in that the collar (43)includes a step (45) that forms a shoulder (47) disposed in the radialplane, which grips over the annular edge (31) of the external supportstructure (29) of the respectively adjacent candle filter (3).
 11. Thefiltering device according to claim 1, characterized in that an axiallyprotruding removal part (33, 35) is formed in one piece with the collar(43) of the external support structure (29) intended for removing therespective filter element from the filter housing.
 12. The filteringdevice according to claim 1, characterized in that an axially protrudingremoval part (39, 41) is disposed on the closed, thicker end of theinternal support structure (13) intended for removing the respectivefiltering element from the filter housing.
 13. A filtering element thatis provided for use according to claim 1, having the shape of a taperedcandle filter (3), with an internal filter cavity (11) that issurrounded by a filter medium (21), characterized in that the internalfilter cavity (11) is closed on the thicker end (19) thereof andincludes a fluid passage (9) on the more slender end thereof that can bebrought into fluid communication with a fluid opening (5), which isdisposed in a base plate (1) of the associated filter housing that isconfigured as a connection plate.
 14. The filtering element according toclaim 13, characterized in that said filtering element includes asupport structure (13) that surrounds the internal filtering cavity (11)for the filter medium (21) that is extended at the more slender endthereof (19) by a connection tube (25) that extends the fluid passage(9), which engages, in the functional position, in the respective fluidopening (5) of the base plate (1) of the housing.